Form for concrete structure



y 24, 1955 N. R. BURKHALTER FORM FOR CONCRETE STRUCTURE 3 Sheets-Sheet 1 Filed March 24, 1954 Fig.

IN V EN TOR.

1 Norfon P. Burkfm/ler l46iL N. R. BURKHALTER FORM FOR CONCRETE STRUCTURE May 24, 1955 3 Sheets-Sheet 2 Filed March 24. 1954- m.M/m m 9V9 I M 3 k r u 5% mw H 0 N y 24, 1955 N. R. BURKHALTER 2,708,780

FORM FOR CONCRETE STRUCTURE Filed March 24, 1954 3 Sheets-Sheet 3 Nor/0n R Burk/ral/er I INVENTOR.

FORM FOR CONCRETE STRUCTURE Norton R. Bnrkhalter, Bryan, Tex. Application March 24, 1954, Serial No. 418,290 2 Claims. (ores- 121 This invention relates to a form for prefabrication of concrete bridges, tunnels and like structures, and has for its primary object the provision of means for casting concrete sections of service tunnels and bridges with semidry mix concrete, so that the forms may be removed immediately and reused.

The construction of this invention features a plurality of sections which are hingedly secured to each other to form the concrete sections. Each of the forms is provided with form plates having spaced parallel ribs attached thereto. Some of the ribs have overlapping portions which have apertures therethrough which are adapted to be aligned with apertures in the ribs of the next adjacent sections so that the sections may be hingedly secured together.

Another object of this invention resides in the provision of a precast concrete bridge or tunnel which employs novel means for erecting such structures.

A further object of the present invention resides in the provision of precast elements for use in erecting concrete bridges and tunnels which employ novel means for forming mortar grooves therebetween so that the various elements may be securely locked together.

Still further objects and features of this invention reside in the provision of a form for casting concrete structures that is strong and durable, simple in construction and manufacture, so arranged that it may be removed from the structure without disturbing the structure; and which is inexpensive to manufacture.

These, together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this form for concrete structures, a preferred embodiment of the form and of the structures produced therewith being shown in the accompanying drawings, by Way .of example only, wherein:

Figure 1 is a plan view of the mold comprising the present invention;

Figure 2 is an end elevational'view of the mold;

Figure 3 is a vertical sectional view as taken along the plane of line 3-3 in Figure 2;

Figure 4 is a perspective view of a mold utilized to form the base sections of the precast concrete bridges or tunnels;

Figure 5 is a vertical sectional view as taken along the plane of line 5-5 in Figure 4.

Figure 6 is a plan view of the mold utilizing extension elements;

Figure 7 is a perspective view of one form of molded concrete structure;

Figure 8 is a perspective view of molded concrete structure;

Figure 9 is a perspective view of one of the molded concrete structures utilized in the service bridge or tunnel assembly;

Figure 10 is a perspective view of one of the base members;

a modified form of nited States Patent O ice Figure 11 is a perspective view of one of the extension members;

Figures 12, 13 and 14 are perspective views of core sections utilized with the molds; and

Figure 15 is an elevational view of a composite structure utilizing the elements produced from the mold.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral 10 generally designates the mold for forming the concrete structure comprising the present invention. This mold is formed from a pair of substantially L-shaped mold sections 12 and 14 having form plates 16 and 18, respectively. Positioned on the form plate 16 are a pair of spaced ribs 2d, while a pair of spaced ribs 22 are secured to the form plate 13.

Leg sections 24 and 26 also form part of the mold 10 and include form plates 28 and 30 having pairs of ribs 32 and 34 attached thereto. As can be seen best in Figure 1, the ribs 32 and 34 have portions 36 and 38 extending beyond the form plates 2% and Si and normal to portions thereof so as to overlap the ribs 20 and 22. Aligned apertures are formed in the ribs 2d and 32 and a pin 40 extends through these apertures to pivotally attach the leg section 24 to the L-shaped section 12. Additionally, pin 42 extends through aligned apertures in the ribs 38 and 22 to pivotally attach the leg section 26 to the L-shaped section 14. Pin 44 also extends through aligned apertures in the ribs 22 and 38 for locking the leg section 26 to the L-shaped section 14 while pin 46 is utilized for locking the leg section 24 to the L-shaped section 12.

A pair of foot sections 48 and 50 are pivotally attached by means of pins 52 and 5'4 which extend through the L-shaped ribs 56 and 58 thereof and through the ribs 241 and 32 of the L-shaped section 12 and the leg section 24. The foot sections 43 and 5% include form plates 60 and 62 and pins 64 and 66 are utilized to lockingly hold the foot section 48 in position while the pins 67 and 68 lock the foot section 50 in position.

Secured to the various form plates of the mold 10 are wedge-shaped members, such as the wedge-shaped member 70, which is secured to the form plate 14 as well as the other wedge-shaped member 72 likewise secured to the form plate 14. Additionally, a wedge-shaped member 74 is secured to the form plate 3%. These wedges are provided for forming bevels in the completed cast structures for a purpose to be henceforth described.

Extensions (not shown) can be utilized between the L- shaped section 14 and the leg section 26 as Well as between the L-shaped section 12 and the leg section 24 to increase the dimensions of the form.

It is to be recognized that should it be desired to form structures of other dimensions, extensions of the type as is shown in Figures 6 and 11 and indicated by reference numerals 75 can be utilized. These extensions have ribs '78 provided with apertures therethrough which are adapted to overlie the various ribs of the members of the mold to which they are attached. It is to be noted that wedge-shaped portions may be provided for the extensions 76, as may be desired. Pins, as at 82 and 84, may be utilized to hold these extensions 76 in position.

Referring now to Figures 4 and 5, it will be noted that herein is disclosed a substantially elongated rectangular mold for casting the base members. This mold includes a pair of longitudinal sections 9d and 92 which are interconnected by lateral sections 94 and 96. The longitudinal sections include face plates 98 and 1% which have outwardly extending ribs 102 and W4 attached, respectively, thereto. The base plates 106 and 103 of the lateral sections 94 and 96 each has a rib attached thereto, such as the ribs 110 and 112. The ribs N2, 104, 110 and 112 overlap each other and are interconnected by pins 114 which extend through aligned apertures in the ribs. The form plates 106 and 168 have V-shaped recesses 116 therein for receiving and supporting a substantially elongated core 118 which is trapezoidal in cross-section and which is adapted to form a groove 120 in the base piece which is of elongated rectangular shape as is shown at 122 in Figure 10.

Utilizing the form 10, a molded concrete structure, as is illustrated in Figure 8 is obtained. This structure is generally indicated by reference numeral 124 and includes a pair of vertically extending leg portions 126 and 128 interconnected by an upper cross portion 130. The wedge portions 70, 72 and 74 form beveled edges 132, 134 and 136 in the completed structure 124. These beveled sections are highly advantageous since when the sections 124 are positioned in abutting relationship, mortar may be positioned within the beveled portions between the beveled portions and the adjacent surface of the abuting structure 124.

Should the structure as is shown in Figure 7 and gen erally designated by reference numeral 138 be desired for constructing the composite tunnel or bridge, as is generally indicated by reference numeral 140 in Figure 15, core pieces of the shape as is shown in Figure 12 and indicated by reference numeral 142 are utilized and positioned in the upper corners of the mold 10, as can be best seen in Figure 1. The utilization of these core pieces 142 which are formed of hollow metallic structure permits the cross-member 144 of the structure 138 to have recesses 146 and 14-8 in the upper edges thereof. The cross-member 144 interconnects legs 147 and 149 of the structure 138, the legs 147 and 149 being beveled as at 150 and 152, while the cross-member 144 is beveled as at 154. These bevels are for the purpose of receiving mortar for bonding adjacent structures together. This can be best seen in Figure 15, the legs 147 and 149 are positioned within the recesses 120 of a pair of adjacent base members 122. It is to be noted that in addition to the concrete structures 138 used in forming the bridge or tunnel 140, elements of the type generally designated by reference numeral 156, as in Figure 9, are utilized. These elements include legs 158 as well as cross portions 160 attached to the upper part of the legs 158.

The legs 158 as well as the cross portions 160 are beveled,

as at 162 and 164, for reception of mortar for interlocking the building elements 156 with the next adjacent building structure. These elements 156 may be utilized to form openings in the bridges or tunnels, or may be utilized to form the three-part conduit, as is shown in Figure 15 with the cross portions 160 being received in the recesses 146 and 148. Core pieces, as generally indicated by reference numeral 166 and shown in Figure 14, are utilized in the mold 10 to form the structures 156.

Should it become desirable to shorten the legs of the various concrete structures formed, core pieces of rectangular shape and generally designated by reference numeral 168, as shown in Figure 13, can be utilized.

After a careful consideration of the foregoing specification and accompanying drawings, it can be readily seen that utilizing the various core pieces as well as the extensions, various sizes and shapes of concrete forms can be readily and easily constructed. Further, the form may be utilized for casting concrete sections utilizing a semidry mix concrete. With the mold 10 lying on a preferably all concrete floor, the semi-dry concrete mix is poured into the form and then may be vibrated, with the reinforcing steel tied together in the mold. it, however, tampers are to be used, then the reinforcing steel must be added as the form is filled. Using tampers, certain of the pins interconnecting the various mold sections together are removed so that the forms will hinge or fold away from the concrete so as not to damage the concrete when the mold sections are removed. After the mold sections have been removed, the structure may be allowed to set and then allowed to cure.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A mold for forming concrete structures comprising a plurality of mold sections, each of said mold sections including form plates, and pairs of spaced ribs secured to and extending beyond said form plates, said form plates being arranged in edgewise abutting relationship with said ribs of one form plate overlapping the ribs of an adjacent form plate, said ribs having aligned apertures therethrough and pins extending through said apertures hingedly securing said sections together, said mold being of substantially U-shape and having a pair of spaced legs interconnected by a cross portion and including inner and outer substantially L-shaped sections, said L-shaped sections forming one leg and the cross portion, inner and outer leg sections having form plates extending normal to parts of the form plates of said L-shaped sections, said leg sections having ribs extending normal to the form plates thereof, and foot sections interconnecting said leg sections including form plates having substantially L-shaped ribs secured thereto.

2. A mold for forming concrete structures comprising a plurality of mold sections, each of said mold sections including form plates, and pairs of spaced ribs secured to and extending beyond said form plates, said form plates being arranged in edgewise abutting relationship with said ribs of one form plate overlapping the ribs of an adjacent form plate, said ribs having aligned apertures therethrough and pins extending through said apertures hingedly securing said sections together, said mold being of substantially U-shape and having a pair of spaced legs interconnected by a cross portion and including inner and outer substantially L-shaped sections, said L-shaped sections forming one leg and the cross portion, inner and outer leg sections having form plates extending normal to parts of the form plates of said L.-shaped sections, said leg sections having ribs extending normal to the form plates thereof, and foot sections interconnecting said leg sections including form plates having substantially L- shaped ribs secured thereto, and wedge-shaped members secured to at least some of said form plates.

References Cited in the tile of this patent UNITED STATES PATENTS 969,232 Winterfield Sept. 6, 1910 1,030,638 Binning June 25, 1912 1,219,689 Baldwin Mar. 20, 1917 1,246,404 Dunning Nov. 13, 1917 1,303,741 Thomas May 13, 1919 1,658,738 Peterson Feb. 7, 1928 1,721,514 Henry July 23, 1929 2,006,132 Fleming et al. June 25, 1935 2,155,121 Finsterwalder Apr. 18, 1939 2,255,480 Connor et al. Sept. 9, 1941 2,367,486 Denham Jan. 16, 1945 2,558,615 Johnson June 26, 1951 2,610,381 Rosati et al Sept. 16, 1952 

